The present invention relates to a mirror transducer control circuit for ring laser gyros. More, particularly, the present invention relates to a piezoelectric drive circuit for such transducers.
Ring laser gyros require that laser path length be maintained substantially constant. This is so since the laser beam intensity is dependent upon the path length. Variations in the beam intensity can adversely affect the performance parameters of the gyro, i.e., gyro errors. In order to maintain the ring laser path length constant, a mirror transducer is commonly employed.
Path length control in ring laser gyros has generally been provided by a variety of piezoelectric transducer assemblies. Such assemblies include one or more piezoelectric elements. Examples of piezoelectric transducer assemblies used in ring laser gyro applications are illustrated in U.S. Pat. No. 3,581,227 issued to Podgorski, U.S. Pat. No. 4,383,763 issued to Hutchings et al., U.S. Pat. No. 4,691,323 issued to Ljung, et al., and U.S. Pat. No. 4,488,080 issued to Baumann.
Ljung et al., and Hutching et al. teach the use of a double diaphragm mirror assembly which includes a piezoelectric driver assembly. The mirror assembly includes a central post which is coupled to a driver assembly. The driver assembly is a cup-shaped metallic driver fixture having an annular diaphragm extending between an integral central member and outer rim member. The central member is rigidly coupled to or attached to the central post of the mirror assembly. A pair of symmetrical piezoelectric annular disks are positioned on opposite sides of the annular diaphragm to provide transducer action.